It's also the season for the tree scheme. Several viewers have told 2 Wants to Know the schemers are making the rounds.

Tree trimming isn't cheap, which is why when a worker knocks on your door or catches you raking leaves and says they can save you money, you might be tempted to take them up on their offer. But you should watch out.

Kevin Hinterberger, President of the Greensboro Better Business Bureau, said, "If they're using high-pressure sales tactics, if they're making this sound like it's a now or never kind of deal, take a step back. If it's a good deal today, it'll be a good day tomorrow."

The Better Business Bureau lists these as other red flag warnings:

-Workers who come to you saying you need work done

-Asking for cash upfront, before the work is done

-Claiming they've done work for a neighbor, but not giving you time to check a reference

Hinterberger said, "The scam artists use high pressure sales tactics and try to make people seem like if you're not taking advantage of this offer you're somehow not smart. [That's] Just not the case. You need to stand firm. If someone makes you feel uneasy, if you're not comfortable, tell them to leave."

If they don't want to leave, you can always call the police. In Greensboro, anyone doing work like tree trimming, roofing, driveway paving-- is supposed to have a privilege license. The color changes every year. This year, it's orange. Chances are the schemers aren't going to be able to show you one. But no matter where you live -- schemers are around. They're trying to trim your trees, put asphalt on your driveway or clean your gutters for a price that's too good to be true. But If they don't do the work fully, or if the work is haphazard, is it a crime? The short answer is no.

Greensboro Police Officer Doug Campbell said, "This becomes criminal when there is intent to deceive right from the start. It just can't be a misunderstanding or disagreement. We have to show in court how the contractor meant to steal your money."

With any kind of work, you should get a written contract or receipt. It should clearly outline what work is going to be done and what kind of payment is to be made. That is your proof. Otherwise it becomes a he-said, she-said situation. If you have don't have proof, should you still call police? They say yes. If they get one or two calls, they chalk it up to a simple disagreement. If they get a dozen, they know there is a trend and can warn others in the area.